switch to representing CVs as words for the compression function

The portable implementation was getting slowed down by converting back
and forth between words and bytes.

I made the corresponding change on the C side first
(https://github.com/veorq/BLAKE3-c/commit/12a37be8b50922a358c016ba07f46816a3da4a31),
and as part of this commit I'm re-vendoring the C code. I'm also
exposing a small FFI interface to C so that blake3_neon.c can link
against portable.rs rather than blake3_portable.c, see c_neon.rs.

1 files changed, 3 insertions, 1 deletions

diff --git a/build.rs b/build.rs
index e45d813..f85959e 100644
--- a/build.rs
+++ b/build.rs
@@ -44,8 +44,10 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
 
     if defined("CARGO_FEATURE_C_NEON") {
         let mut build = new_build();
+        // Note that blake3_neon.c normally depends on the blake3_portable.c
+        // for the single-instance compression function, but we expose
+        // portable.rs over FFI instead. See c_neon.rs.
         build.file("src/c/blake3_neon.c");
-        build.file("src/c/blake3_portable.c");
         // ARMv7 platforms that support NEON generally need the following
         // flags. AArch64 supports NEON by default and does not support -mpfu.
         if is_armv7() {